EditorialExploding myths about medically unexplained symptoms
Introduction
The term “medically unexplained symptoms” has had a chequered history. It has been widely used in clinical medicine and in many research studies but it has come under increasing criticism as it lacks precision and may perpetuate mind–body dualism. This paper aims to dismiss three myths concerning medically unexplained symptoms and, instead, suggests an alternative and more holistic way of regarding these symptoms.
The term “medically unexplained symptoms” refers to the large proportion of patients seeking medical care whose symptom(s) cannot be explained by a recognised general medical illness; they may form half of new medical clinic patients [1]. This group of patients includes those with a functional somatic syndrome (e.g. chronic fatigue or fibromyalgia), those with a diagnosis of somatoform disorder, somatization disorder or Bodily Distress Syndrome and those who receive a diagnosis of “symptom, signs not elsewhere classified” (ICD 10), [1], [2], [3]. These diagnostic groups overlap and a proportion of each will fulfil also the criteria for an anxiety or depressive disorder (Fig. 1).
Section snippets
Myth 1 Medically unexplained symptoms indicate an underlying psychiatric disorder
The proportion of patients with medically unexplained symptoms who also have anxiety or depressive disorders increases in proportion to the number of somatic symptoms. Of primary care patients with 4–5 medically unexplained symptoms one third have an anxiety or depressive disorder; the proportion rises to a half in patients with 6–8 medically unexplained symptoms and up to 80% in patients with 9 or more medically unexplained symptoms [4], [5]. Most patients presenting to medical clinics with
Myth 2 Medically unexplained symptoms are persistent, disabling and resistant to treatment
A systematic review concluded that most medically unexplained symptoms are not persistent;, 50% to 75% improve over 1 year [10]. This review found some evidence that a large number of somatic symptoms at baseline were associated with persistent symptoms and it is the small number of patients with very numerous medically unexplained symptoms who generally report persistent symptoms and marked impairment. A systematic review of treatment outcome concluded that positive results were more often
Myth 3 Medically unexplained symptoms have an aetiology distinct from organic disorders
Relatively little work has assessed the risk factors for developing medically unexplained symptoms. Although prior psychiatric disorder is a risk factor, this is not the sole explanation [12], [13] and evidence concerning the functional somatic syndromes suggests that both “organic” and psychological causal factors are involved. Prospective studies of irritable bowel and chronic fatigue syndromes have demonstrated that both prior infection and anxiety or depression are independent risk factors
A more holistic approach
Recent research has moved away from medically unexplained symptoms using, instead, measures of all somatic symptoms, i.e. including both medically explained and unexplained somatic symptoms. Such studies show clearly that a high total number of somatic symptoms is associated with impaired health status and high healthcare use [16]. A high number of somatic symptoms is associated with female gender, anxiety, depression and general medical illnesses but even after adjustment for these variables
Conclusion
It has been suggested recently that we need to view risk factors for all psychiatric disorders using multilevel empirically based pluralism and that the biopsychosocial model needs to be updated [25]. The concept of medically unexplained symptoms also needs to be updated and this brief review suggests that the dimension of total somatic symptoms scores can best be seen as one of several dimensions which predict outcome; we need to understand the risk factors for each of these dimensions
Acknowledgement
This editorial is based on the Frits Huyse Award Lecture given by Francis Creed at the European Association of Psychosomatic Medicine, Nuremberg 4th July 2015.
References (25)
- et al.
One single diagnosis, bodily distress syndrome, succeeded to capture 10 diagnostic categories of functional somatic syndromes and somatoform disorders
J. Psychosom. Res.
(May 2010) - et al.
Depressive and anxiety disorders in patients presenting with physical complaints: clinical predictors and outcome
Am. J. Med.
(November 1997) - et al.
The relationship between somatisation and outcome in patients with severe irritable bowel syndrome
J. Psychosom. Res.
(Jun 2008) - et al.
The proposed diagnosis of somatic symptom disorders in DSM-V to replace somatoform disorders in DSM-IV—a preliminary report
J. Psychosom. Res.
(2009) - et al.
Medically unexplained symptoms, somatisation disorder and hypochondriasis: course and prognosis. A systematic review
J. Psychosom. Res.
(May 2009) - et al.
Management of functional somatic syndromes
Lancet
(March 17 2007) - et al.
Relative importance of enterochromaffin cell hyperplasia, anxiety and depression in post-infectious IBS
Gastroenterology
(December 2003) - et al.
Are medically unexplained symptoms and functional disorders predictive for the illness course? A two-year follow-up on patients' health and health care utilisation
J. Psychosom. Res.
(Jul 2011) - et al.
Do illness perceptions predict health outcomes in primary care patients? A 2-year follow-up study
J. Psychosom. Res.
(Feb 2007) - et al.
A high physical symptom count reduces the effectiveness of treatment for depression, independently of chronic medical conditions
J. Psychosom. Res.
(Mar 2013)